This invention relates to vibration densitometers, and more particularly to a shield in which a densitometer probe can be contained so as to create vortex shedding, and means to produce an output directly proportional to mass flow rate with or without an output directly proportional to density or specific gravity. Shields have been used in the prior art, but not of the desirable construction for vortex shedding. However, see, for example, copending application Ser. No. 634,047 Nov. 21, 1975, by Joseph J. Ponzi for VIBRATION DENSITOMETER WITH PROBE ASSEMBLY HAVING DOUBLE CALIBRATION SHIFT SUPPRESSION assigned to the assignee of the present invention.